The present invention relates to a package containing a product and a flexible, selfcontained heating/cooling element. More particularly, the invention relates to a package containing a flexible, self-contained, chemical-based heating/cooling element that is at least partially immersed in a product.
Various types of self-heating containers are known in the art for heating the contents (mainly foodstuffs) to a desired temperature. For example, various external heating systems that heat a foodstuff or beverage through conductive heating are known. For example, U.S. Pat. No. 4,895,135 discloses a system that utilizes a partial form of immersion heating and can be described as a container body [that] is formed of a sheet member including a metal foil and a synthetic resin layer attached on at least one side of the metal foil. The sheet member is folded to have a W-shaped cross section and is heat-sealed along the vertical and upper edges. The inverted V-shaped portion of the folded sheet defines a chamber for accommodating the envelope outside the container body. Further, U.S. Pat. No. 4,895,135 discloses a self-heating container in which the primary bag has a notch formed to permit rupture of the primary bag upon pulling of one end of the bag. The self-heating container a water permeable envelope on at least the lower surface facing the primary bag. A self-heating container wherein the outer shell member comprises a receptacle and a cover removably secured to the receptacle. This uses an activation means whereby a pull-tab is used to break the primary water bag and the pressure of the expanding gases from a first reaction breaking another fluid bag to start another reaction. Further, the invention as disclosed is an open system with the opportunity for the slurry of the mixed aqueous solution and reactant to spill out if the package is mishandled. The package is a relatively complex design in which the reactive components may come into contact with a user or the product being heated. Also, the heating element is located on an exterior of the package, which may allow heat to migrate outside of the package.
U.S. Pat. No. 5,263,929 describes an infusion administration container for infusing a physiologic fluid into an animal, which comprises: a first flexible bladder divided into at least two compartments separated from one another, each of the compartments containing at least one first chemical agent; a second flexible bladder disposed outside the first flexible bladder and containing at least one second chemical agent, the first and second chemical agents when combined resulting in an exothermic reaction; passageways interconnecting each of the compartments of the first bladder with the second bladder; manually openable closure means disposed within each of the passageways. The activation mechanism consists of a dial or twist-tie to turn that allows water to flow into the system from outside a connected container to the fluid to be warmed, activation means incorporates additional components outside of the package itself. Their embodiment also has a discontinuous heating element where the components are not co-located within one packaging system, thus not allowing immediate fluid uptake for a faster heating response. Also, with the discontinuous system an inefficient use of heat transfer is afforded by having additional volume outside of the package for hot air to travel to which is expended to the environment instead of the product to be heated. Last, such an embodiment would require complicated manufacturing steps and would not be an innocuous system for the dispensing of consumer heated products from small sizes packaging.
U.S. Pat. No. 5,979,164 relates generally to containers for heating or cooling materials such as food, beverages, medicines, and the like and, more specifically, to a container that includes an internal module that adds heat to or removes heat from the materials in the surrounding container. U.S. Pat. No. 5,979,164 further discloses a flexible embodiment of a container that comprises a container body having a tapered, tube-like or pouch-like shape and made of a flexible or pliable material such as soft plastic. Soft metal foil of the type commonly used in toothpaste tubes would also be suitable. This patent utilizes the distal end of an elongated member to break a barrier to allow mixing of reactants when the elongated member is extended. Again, the patent discloses a relatively complex activation means that requires additional activation elements.
The present invention provides a temperature modifying system for heating or cooling a product that includes a flexible outer container containing a product and a self-enclosed temperature-changing element. The temperature-changing element includes a flexible pouch at least partially immersed in said product. The flexible film pouch may have two components separated by a rupturable barrier that is adapted to burst under an application of pressure allowing the two components to combine or react in an exothermic or endothermic event. The flexible film pouch may alternatively include a saturated salt solution that generates as it drops out of solution.